Spring clamp for a support leg

ABSTRACT

A detachable support for a workpiece, and in particular a bending brake, includes a workpiece support and a clamp pivotally attached to the workpiece support. The clamp further comprises a lever that pivots about a pivot axis relative to the workpiece support between an unclamped position and a clamped position, the clamp being biased toward the clamped position. In operation, a user pivots the clamp into an unclamped position, places the detachable support structure into positional engagement with the workpiece, and then releases the clamp into clamping engagement with the workpiece.

FIELD OF THE INVENTION

The present invention relates to clamps in general, and more specifically to a spring clamp for a support leg for attachment to, for example, a sheet bending brake.

BACKGROUND

Bending brakes are utilized in numerous industries, especially in the aluminum siding industry, to bend workpieces of substantially flat sheet material (e.g. aluminum), in situ, through a wide range of angles. A bending brake is described in U.S. Pat. No. 4,351,176, incorporated by reference herein, by the present inventor. Such bending brake is now also being used to bend vinyl material that, like aluminum, is formed into coils to promote transportability.

Typical bending brakes also have pairs of support legs that are bolted or otherwise fixed thereon and usually foldable thereunder. Such fixed leg pairs tend to seriously impede the process of loading/unloading the brakes onto/from the roof racks of pickup trucks used to transport the brakes from job site to job site. Moreover, fixed leg pairs prevent the brakes from being used directly on scaffolds, forcing workers to pass aluminum or vinyl material down from the scaffolds every time they need to cut, bend, or otherwise manipulate such material.

Detachable brake support legs were developed to overcome the problems associated with fixed leg supports. Various types of detachable brake supports are described in U.S. Pat. No. 5,860,312, incorporated by reference herein, also to the present inventor. One example is shown herein in FIG. 1, wherein a pivoting handle 20 is used to engage a bending brake casting 30 to provide sufficient leverage to secure a pair of legs 40 thereto. A pivoting handle of the type shown in FIG. 1, however, requires a two-handed manual manipulation. First, the bending brake casting 30 must be properly aligned with the support legs 40. Then, while supporting the bending brake casting in alignment, the pivoting handle 20 must be manipulated so that it is properly engaged with the bending brake casting 30. This two-step operation can be difficult in the field, particularly on a non-level or unstable footing.

Other prior art solutions, such as that shown in U.S. Pat. No. 6,532,789 and U.S. Pat. No. 6,854,314, utilize bulky stands that are not easily portable or transportable, or are otherwise suited for working environments designed for fixed leg support models. Accordingly, there is a need for a detachable support structure, particularly for a bending brake, that is easy to attach, easy to remove, easy to transport, and that does not detract from the portability of the device as a whole. In addition, there is a need for a detachable support structure that can be manipulated, positioned and preferably attached with minimal effort, and more preferably with one hand.

SUMMARY

A detachable support structure for a workpiece, and in particular a bending brake, comprises a workpiece support and a clamp pivotally attached to the workpiece support. The clamp further comprises a lever that pivots about a pivot axis relative to the workpiece support between an unclamped position and a clamped position, the clamp being biased toward the clamped position. In operation, a user pivots the clamp into an unclamped position, places the detachable support structure into positional engagement with the workpiece, and then releases the clamp into clamping engagement with the workpiece.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a prior art illustration of a detachable support structure for a bending brake.

FIG. 2 illustrates one embodiment of a detachable support of the present invention.

FIG. 3 is an exploded view of the detachable support of FIG. 2.

FIG. 4 is a simplified cross-sectional view taken through the clamp of the detachable support.

FIG. 5 is a view of the clamp of FIG. 4 with the clamp lever biased into an unclamped position.

FIG. 6 is a view of the clamp of FIG. 4 with a workpiece attached.

FIG. 7 illustrates a user preparing to attach the detachable support of FIG. 2 to a workpiece.

FIG. 8 illustrates a user attaching the detachable support of FIG. 2 to a workpiece.

FIG. 9 illustrates the detachable support of FIG. 2 attached to a workpiece.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following detailed description is of the best mode or modes of the invention presently contemplated. Such description is not intended to be understood in a limiting sense, but to be an example of the invention presented solely for illustration thereof, and by reference to which in connection with the following description and the accompanying drawings one skilled in the art may be advised of the advantages and construction of the invention. In the various views of the drawings, like reference characters designate like or similar parts.

The following detailed description also references one embodiment of a detachable support for a workpiece, where the workpiece is illustrated as a sheet bending brake. Other embodiments are contemplated where the workpiece is not a sheet bending brake, it being understood that the detachable support could be constructed to engage any type of workpiece desired by the user. However, for purposes of convenience and illustration herein, the workpiece will be described as a bending brake.

FIGS. 2-9 illustrate one embodiment of a detachable support 100 for a workpiece 50, the workpiece 50 illustrated in FIGS. 7-9 as a bending brake for purposes of convenience as noted above. The detachable support 100 generally comprises an inverted “U”-shaped leg 105 (FIG. 2) with a workpiece support 110 provided thereon. It will be understood that while a “U”-shaped leg is shown, other constructional variations will be operable as desired by the user. Furthermore, while a workpiece support 110 is shown mounted to a leg 105, it will be appreciated that the workpiece support 110 could be integrated into the construction of the leg 105 during the manufacturing process as desired.

A clamp 200 (FIG. 2) is pivotally attached to the workpiece support 110 and further comprises, as shown in FIG. 3, a lever 250 having a first end 260 for pressing engagement by a user and a second end 270 for engagement with a workpiece 50. The lever 250 moves or pivots about a pivot axis 252 relative to the workpiece support 110 between an unclamped position 254 (FIGS. 5, 7, 8) and a clamped position 256 (FIGS. 4, 6, 9), the pivot axis 252 being parallel to the longitudinal axis 112 (FIG. 2) of the workpiece support 110. The clamp 200 is attached to the workpiece support 110 by a pivot pin 265 that is secured to a bifurcated channel 116 formed in an interior 118 of the workpiece support 110. A biasing member 275 is secured around the pivot pin 265 and is arranged to bias the lever 250 toward the clamped position 256. While a biasing member 275 in the form of a coil spring is shown, it will be appreciated that other biasing constructions can be used as desired. The biasing member 275 is omitted from FIGS. 4-6 to better illustrate the movement of the lever 250.

The workpiece support 110 further comprises a first guide recess 120 (FIGS. 2 and 3) extending the length 114 of the workpiece support 110 for receiving a portion of a workpiece 50. A second guide recess 122 (FIGS. 4 and 5) extending the width 205 (FIG. 3) of the clamp 200 is defined when the second end 270 of the lever 250 is in the clamped position 256 as shown in FIGS. 4 and 6. The first and second guide recesses 120, 122 respectively cooperate to position and engage the workpiece 50 as shown in FIG. 6, while the second end 270 of the lever 250, and in particular the underside 272 of the second end 270, clamps down on the workpiece 50 when the lever 250 is in the clamped position 256 (FIGS. 4, 6, 9). While first and second guide recesses 120, 122 respectively are shown and described to engage and secure a particular workpiece topography, it will be understood that other methods of engaging workpieces having other constructions are herein contemplated.

FIGS. 7-9 illustrate one example of an attachment of the detachable support 100 of the present embodiment to one side of a workpiece or a bending brake 50. FIG. 7 illustrates a user 300 gripping the detachable support 100 with one hand 310, while manipulating the bending brake 50 with the other hand 320 for purposes of attaching the support 100 to the brake 50 along the transverse or widthwise axis of the brake 50 (i.e., along an end of the brake). A particular benefit of the construction of the detachable support 100 of the present embodiment is a user's ability to simultaneously grip the leg 105, the workpiece support 110, and the clamp 200, and manipulate all elements as a single unit. Furthermore, by positioning the clamp 200 in the center of the workpiece support 110, a user is able to simultaneously grip the leg 105 with the user's fingers and bias the first end 260 of the clamp lever 250 into an unclamped or open position 256 with the user's palm in preparation for engagement with the bending brake 50. Alternatively, or in addition to the biasing of the first end 260 of the clamp lever 250, a cam surface 271 (FIG. 4) is provided on the second end 270 for urging the clamp lever 250 into an unclamped or open position upon contact with the brake 50. Thus, the cam surface 271 alone can act to open the clamp lever 250 if the first end 260 is not depressed before making contact with the brake 50. However, the opening of the clamp lever 250 with the cam surface 271 is unlikely to occur in most instances since it will be appreciated that the clamp end 260 will likely be gripped simultaneously with the leg 105 during attachment of the support 100 to the brake 50 as shown in FIG. 7.

FIG. 8 illustrates the positioning of the bending brake 50 in close proximity to the detachable support 100, whereby the workpiece support 110 is maneuvered, with the clamp lever 250 biased in the open position 256, to engage the brake 50 within the first and second recesses 120, 122 respectively (see FIGS. 4, 5). Once the brake 50 is properly positioned, the clamp lever 250 is released by the user so that the second end 270 biases against the brake 50 to retain a secure engagement therewith as shown in FIG. 9. Thereafter, a second detachable support (not shown) is attached to the other side of the bending brake in preparation for use. To detach the support 100 from the brake 50, a user simply has to press the first end 260 of the clamp lever 250 to release the second end 270 of the clamp lever 250 from clamping engagement with the brake 50, and separate the brake 50 from the workpiece support 110 in a manner similar to that shown in FIG. 7.

The above embodiment describes a detachable support structure, particularly for a bending brake, that is easy to attach, easy to remove, easy to transport, and that does not detract from the portability of the device as a whole. It will be appreciated the detachable support structure of the described embodiment can be used with workpieces other than bending brakes, such as, for example, table saws, saw horses, etc. In addition, it will be appreciated the detachable support structure of the described embodiment can be used with other items such as ping pong tables, card tables, or any items that could benefit from detachable legs.

While the present invention has been described at some length and with some particularity with respect to the described embodiment, it is not intended that it should be limited to any such particulars or embodiment, but it is to be construed with references to the appended claims so as to provide the broadest possible interpretation of such claims in view of the prior art and, therefore, to effectively encompass the intended scope of the invention. Furthermore, the foregoing describes the invention in terms of embodiments foreseen by the inventor for which an enabling description was available, notwithstanding that insubstantial modifications of the invention, not presently foreseen, may nonetheless represent equivalents thereto. 

1. A detachable support leg for a workpiece comprising: a) a workpiece support having a longitudinal axis; b) a clamp pivotally attached to the workpiece support and further comprising a lever that pivots about a pivot axis relative to the workpiece support between an unclamped position and a clamped position; and c) a biasing member for biasing the lever toward the clamped position.
 2. The detachable support leg of claim 1, wherein the pivot axis is parallel to the longitudinal axis of the workpiece support.
 3. The detachable support leg of claim 2, wherein the workpiece support further comprises a first guide recess for receiving a portion of a workpiece.
 4. The detachable support leg of claim 4, the lever further comprising a first end for engagement by a user and a second end for engagement with a workpiece, the second end of the lever further defining a second guide recess with the workpiece support when the lever is in the clamped position.
 5. The detachable support leg of claim 4, wherein the first guide recess extends longitudinally along a length of the workpiece support.
 6. The detachable support leg of claim 5, wherein the second guide recess extends along a width of the clamp.
 7. The detachable support leg of claim 1, wherein the clamp is attached to the workpiece support by a pivot pin, the biasing member being secured around the pivot pin.
 8. The detachable support leg of claim 7, wherein the pivot pin is secured to a bifurcated channel in an interior of the workpiece support.
 9. The detachable support leg of claim 1, wherein the clamp is positioned relative to the detachable support leg such that it can be biased into the unclamped position simultaneously with a positioning of the workpiece support into an engagement with the workpiece.
 10. The detachable support leg of claim 1, wherein the workpiece is a bending brake.
 11. A bending brake comprising at least one removable support leg, the at least one removable support leg further comprising a clamp having a lever that pivots about a pivot axis between an unclamped position and a clamped position, the lever biased toward the clamped position for biased engagement with the bending brake.
 12. The bending brake of claim 11, wherein the bending brake further comprises a longitudinal axis and a transverse axis, and the pivot axis is parallel to the transverse axis of the bending brake.
 13. The bending brake of claim 11, wherein the at least one removable support leg further comprises a first guide recess for receiving a portion of the bending brake.
 14. The bending brake of claim 13, the lever further comprising a first end for engagement by a user and a second end for engagement with the portion of the bending brake, the second end of the lever further defining a second guide recess with the at least one removable support leg when the lever is in the clamped position.
 15. A method of attaching a support leg to a bending brake, comprising: a) providing a support leg with a clamp that moves between an open position and a clamped position; b) simultaneously gripping the support leg and the clamp such that the clamp moves into the open position; c) positioning the support leg into engagement with the bending brake; and d) releasing the support leg with the clamp in the clamped position thereby attaching the support leg to the bending brake.
 16. The method of claim 15, wherein the clamp is pivotally attached to the support leg such that the clamp pivots about a pivot axis between the open and clamped positions.
 17. The method of claim 16, wherein the clamp is biased toward the clamped position.
 18. The method of claim 17, wherein the clamp is centrally positioned on the support leg.
 19. The method of claim 18, wherein the bending brake further comprises a longitudinal axis and a transverse axis, and the pivot axis is parallel to the transverse axis of the bending brake.
 20. The method of claim 19, further comprising attaching another support leg to the bending brake. 